One known method for verifying or authenticating that a particular person is the same person who had previously been identified is to compare that person's fingerprint to a previously obtained fingerprint. According to one conventional method of acquiring fingerprint data, an ink impression of a fingerprint is printed on paper for subsequent scanning into a digital computer. According to this method, the finger is stained with ink each time the fingerprint data is entered. Any uneven coating or bluming of the ink hinders the input operation, as does any lateral motion or shear of the inked finger when applied to the paper. To ensure that enough information is obtained during data input or enrollment, the finger is typically "rolled" across the paper to transfer a greater portion of the surface of the person's finger thereto. While the rolling step increases the overall amount of data acquired, the increased risk of finger shear undermines the integrity of the acquired data. Further, geometric or electronic distortions may be introduced during the process of scanning the data into the digital computer.
According to more modern methods, fingerprints are obtained by reflecting or scattering an image of the finger surface onto an image sensor, such as a charge coupled device. Devices that perform this function are described in, for example, U.S. Pat. Nos. 4,924,085 to Kato et al., 5,088,817 to Igaki et al., and 5,067,162 to Driscoll, Jr., et al., the disclosures of which are hereby incorporated by reference as though set forth in their entirety herein. In each of these systems, a light source is irradiated at a reflected angle onto the edge and groove portions of a fingerprint which has been pressed against a light conducting plate. Depending upon the particular orientation of the light source with respect to the light conducting plate, and the location of the image sensing device, either the reflected or the scattered light from the fingerprint is measured. The image sensor captures the measured light so that the captured fingerprint data can be stored. While these modern methods have simplified the fingerprint data acquisition process, they have not provided a system which ensures that the finger apply even pressure to the platen to obtain a broad print.
One graspable system for identifying an individual is taught in U.S. Pat. No. 4,857,916. This system identifies an individual using a plurality of pressure sensors located across a graspable member for developing a uniquely identifying signal indicative of the pressures exerted by an individual's hand in grasping the graspable member. This system does not acquire the person's fingerprint data, but rather utilizes the pressure points to construct identifying data.
While there has been recognition in the art of the need to position a finger with respect to the finger platen, see for example Kato et al., what has been needed and has heretofore not been fulfilled in the art, is a fingerprint reader apparatus which provides a prehensile shape to permit grasping the fingerprint reader device in a manner so that the person's digit applies even pressure to the platen and thereby allows a broad, even print of the digit to be acquired. Also needed is a fingerprint reader apparatus that provides a prehensile shape with the aforementioned advantages, packaged in a wireless housing for communication with a remote receiving device. Of further benefit to the art, would be such a system that further allows notarization of transactions to authenticate that a transaction to be charged against an account has been authorized by an account holder. The present invention satisfies these and other needs in an ergonomic fingerprint reader apparatus.